Re: [PATCH] install.sh: Preserve directory symlinks

["Thierry Escande" <thierry.escande@xxxxxxxxxx>]

On 3/19/26 14:48, Jan Beulich wrote:
> On 19.03.2026 14:26, Thierry Escande wrote:
>>
>>
>> On 3/19/26 10:31, Jan Beulich wrote:
>>> On 13.03.2026 18:25, Thierry Escande wrote:
>>>> In various distros (i.e. Debian) some folders like /lib or /var/run are
>>>> symlinks. Using the tar option --keep-directory-symlink preserves these
>>>> symlinks.
>>>>
>>>> Signed-off-by: Thierry Escande <thierry.escande@xxxxxxxxxx>
>>>> ---
>>>>  install.sh | 2 +-
>>>>  1 file changed, 1 insertion(+), 1 deletion(-)
>>>>
>>>> diff --git a/install.sh b/install.sh
>>>> index 3e11c4d46f..5d0b7a4933 100644
>>>> --- a/install.sh
>>>> +++ b/install.sh
>>>> @@ -27,7 +27,7 @@ tmp="`mktemp -d`"
>>>>  echo "Installing Xen from '$src' to '$dst'..."
>>>>  (cd $src; tar -cf - * ) | tar -C "$tmp" -xf -
>>>>  
>>>> -(cd $tmp; tar -cf - *) | tar --no-same-owner -C "$dst" -xf -
>>>> +(cd $tmp; tar -cf - *) | tar --no-same-owner -C "$dst" 
>>>> --keep-directory-symlink -xf -
>>>
>>> How compatible (between flavors of tar as well as between versions of GNU
>>> tar) is use of this option?
>>
>> It's supported by GNU tar since version 1.27 (from ~12 years ago) but it
>> seems to be the only implementation that supports it. BSD and busybox
>> don't support it. I didn't check for other implementations.
>>
>> I can add a flavor/version check if that makes sense.
> 
> Possibly. One question then is what the behavior was prior to that option
> having been introduced.

>From the patch at [1] introducing the option, and more precisely the
test done at [2], directory symlinks were simply overwritten.

[1]
https://cgit.git.savannah.gnu.org/cgit/tar.git/commit/?id=2c06a80918019471876956eef4ef22f05c9e0571
[2]
https://cgit.git.savannah.gnu.org/cgit/tar.git/tree/src/extract.c?id=2c06a80918019471876956eef4ef22f05c9e0571#n934

Regards,
Thierry


--
Thierry Escande | Vates XCP-ng Developer

XCP-ng & Xen Orchestra - Vates solutions

web: https://vates.tech